The second-seeded Yellow Jackets (41-16) will face fifth-seeded North Carolina, which beat Boston College 13-5 in the other semifinal Saturday.
Guldberg's home run broke a 1-all tie and came after Nick Wilhite singled with two outs and Luke Waddell walked. Tristin English also homered for Georgia Tech, a solo shot in the second.
Baron Radcliff and Wilhite added two-run hits in a five-run eighth.
Jonathan Hughes (8-2) allowed two hits and one run in five innings in relief.
Third-seeded N.C. State (42-17), 11-0 mercy rule losers to Florida State when they managed just one hit on Friday night, had just six more against three Georgia Tech pitchers.
Copyright 2019 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.